Non-electric delay detonator and assembly of a detonating cord and a delay detonator

Claim 2

A non-electric delay detonator adapted to be actuated by a low-energy detonating cord and comprising a first tubular metal shell (1) integrally closed at one end, said first shell containing, in sequence from the closed end: (a) a base charge (2) of a detonating explosive composition; (b) a priming charge (3) of a heat sensitive detonating explosive composition; (c) a delay charge (5) of an exothermic-burning composition; (d) a tubular rigid metal capsule (6) nested within said first shell and having one open extremity (7) and a closure at the other extremity (8) provided with an axial orifice (9) therethrough, said closure on said capsule being adjacent to said delay charge or to a tubular carrier containing said delay charge; (e) a second tubular metal shell (10) integrally closed at one end, said second shell being deformable and positioned coaxially within said first shell in a manner such as to produce a spacing between the side walls of said second shell and of said capsule, and between the closed end of said second shell and the closure on said capsule; and (f) a percussion-sensitive ignition charge (11) in the spacing between the side walls of said second shell of said capsule, and between the closed end of said second shell and said closure on said capsule, said ignition charge being in contact with said delay charge by virtue of the orifice in the closure on said capsule; means (12, 17) being provided for sealing off said charges from the atmosphere and for preventing the venting of gases resulting from the burning of said ignition charge, an open cavity (13) extending from one end to the other of said second shell for receiving a low-energy detonating cord (21) adapted by its detonation to produce a pressure pulse that causes the ignition of said ignition charge, and said cavity being provided with a cord-retention means (14) for holding said cord coaxially therein.

Claim 3

A detonator as claimed in Claim 1 wherein a delay charge carrier comprising a heavy-walled tube (4) of rigid material containing an axialcore (5) of said delay charge is interposed between said priming charge (3) and the closed extremity (8) of said rigid metal capsule (6), said axial core being coaxial and in communication with the orifice (9) in the closure on said capsule to permit contact between said delay charge and said ignition charge.

Claim 4

A detonator as claimed in Claim 1 or Claim 2 wherein said cord-retention means is an open-ended sleeve (14) having cord-gripping means (15) associated therewith, said sleeve frictionally engaging the inside wall of said second shell (10) and extending from the open end of said second shell toward the center of said cavity (13).

Claim 5

A detonator as claimed in Claim 3 wherein said cord-gripping means comprises at least on inwardly directed prong (15) formed on the inner end of said sleeve.

Claim 6

A detonator as claimed in Claim 3 or Claim 4 wherein the inner end of said sleeve (14) lies in a plane normal to the axis thereof that also passes through said ignition charge (11), or, if not, is spaced from the plane in which the boundary (16) of said ignition charge lies by a distance no greater than about 5.5 millimeters.

Claim 7

A detonator as claimed in Claim 5 wherein the inner end of said sleeve (14) lies in a plane normal to the axis thereof that is spaced from the bottom of said second shell (10) by a distance no greater than about 8 millimeters.

Claim 8

A detonator as claimed in any one of Claims 3 to 6 wherein said first sleeve (1) is made of metal and, at its outer end, is provided with a lip portion (18) that extends over the end of said second shell (10) or over a conforming lip portion on the end of said second shell.

Claim 9

A detonator as claimed in any one of the preceding claims wherein a deformable grommet (12) is sandwiched between said first and second shells (1, 10) starting from their open ends and extending approximately to the open extremity of said capsule (6), said shells and grommet being held together by one or more circumferential side crimps (19, 20).

Claim 10

A detonator as claimed in any one of the preceding claims wherein said ignition charge (11) is a pressed granular mixture comprising, by weight, at least about 86% red lead; from about 1 to 2.5% boron; and up'to about 11% lead azide, lead styphnate, or a mixture thereof.

Claim 11

A non-electric assembly for initiating a blasting charge comprising a first tubular metal shell (1) integrally closed at one end, said first shell containing, in sequence from the closed end: (a) a base charge (2) of a detonating explosive composition; (b) a priming charge (3) of a heat-sensitive detonating explosive composition; (c) a delay charge (5) of an exothermic-burning composition; (d) a tubular rigid metal capsule (6) nested within said first shell and having one open extremity (7) and a closure at the other extremity (8) provided with an axial orifice (9) therethrough, the closure on said capsule being adjacent to said delay charge or to a tubular carrier (4) containing said delay charge; (e) a second tubular metal shell (10) integrally closed atome end, said second shell being deformable and positioned coaxially within said first shell in a manner such as to produce a spacing between the side walls of said second shell and of said capsule, and between the closed end of said second shell and the closure on said capsule; (f) a percussion-sensitive ignition charge (11) in the spacing between the side walls of said second shell and of said capsule . and between the closed end of said second shell and said closure on said capsule. said ignition charge being in contact with said delay charge by virtue of the orifice in the closure of said capsule; means (12, 17) being provided for sealing off said charges from the atmosphere and for preventing the venting of gases resulting from the burning of said ignition charge, an open cavity (13) extending from one end to the other of said second shell; (g) an end-section of a length of low-energy detonating cord (21) in the cavity of said second shell; and (h) cord-retention means (15) in said cavity for holding said cord in coaxial position therein in a manner such that the plane that passes through the end of the cord within said cavity normal to the cord axis also passes through said ignition charge or if not, is spaced from the plane in which the boundary (16) of said ignition charge lies by a distance no greater than about 2.5 millimeters.

Claim 12

A non-electric assembly for initiating a blasting charge comprising a first tubular metal shell (1) integrally closed at one end, said first shell containing, in sequence from the closed end: (a) a base charge (2) of a detonating explosive composition; (b) a priming charge (3) of a heat-sensitive detonating explosive composition; (c) a delay charge (5) of an exothermic-burning composition; (d) a tubular rigid metal capsule (6) nested within said first shell and having one open extremity (7) and a closure at the other extremity (8) provided with an axial orifice (9) therethrough, the closure on said capsule being adjacent to said delay charge or to a tubular carrier (4) containing said delay charge; (e) a second tubular metal shell (10) integrally closed atome end, said second shell being deformable and positioned coaxially within said first shell in a manner such as to produce a spacing between the side walls of said second shell and of said capsule, and between the closed end of said second shell and the closure on said capsule; (f) a percussion-sensitive ignition charge (11) in the spacing between the side walls of said second shell and of said capsule . and between the closed end of said second shell and said closure on said capsule. said ignition charge being in contact with said delay charge by virtue of the orifice in the closure of said capsule; means (12, 17) being provided for sealing off said charges from the atmosphere and for preventing the venting of gases resulting from the burning of said ignition charge, an open cavity (13) extending from one end to the other of said second shell; (g) an end-section of a length of low-energy detonating cord (21) in the cavity of said second shell; and (h) cord-retention means (15) in said cavity for holding said cord in coaxial position therein in a manner such that the plane that passes through the end of the cord within said cavity normal to the cord axis also passes through said ignition charge or if not, is spaced from the plane in which the boundary (16) of said ignition charge lies by a distance no greater than about 2.5 millimeters.

Claim 13

An assembly as claimed in Claim 10 wherein said detonating cord (21) has an explosive core loading of from about 0.2 to 1 gram per meter of length.

Claim 14

An assembly as claimed in claim 10 or Claim 11 wherein said low-energy detonating cord comprises a continuous solid cord (22) of a deformable bonded detonating explosive composition comprising a crystalline high explosive compound admixed with a binding agent, and a protective plastic sheath (24) enclosing said core.

Claim 15

An assembly as claimed in any one of Claims 10 to 12 wherein said cord-retention means (15) holds said cord (21) in a manner such that.the plane that passes through the end of the cord also passes through said ignition charge (11).

Claim 16

An assembly as claimed in Claim 13 wherein the end of said cord (21) is seated against the closed end of said second shell (10).

Claim 17

A non-electric assembly for initiating a blasting charge comprising a detonator as claimed in any one of Claims 2 to 9 wherein an end-section of a low-energy detonating cord (21) is located in the cavity (13) of the second shell (10) so that the end section of said cord is positioned close enough to the ignition charge (11) to ensure actuation of the ignition charge by outward expansion of said second shell produced by detonation of said cord.

Claim 18

A non-electric delay detonator adapted to be actuated by a low-energy detonating cord, said detonator including a body (1) containing a base charge (2) and a priming charge (3) in close proximity thereto and an ignition charge (11) communicating with the priming charge via a delay charge (5), said detonator body housing an expansion shell (10) which has an opening for admitting a free end of a low-energy detonating cord (21), the ignition charge being present in an annular space between the expansion shell and the detonator body and the expansion shell including cord-receiving means (14) which is positioned with respect to the ignition charge in said annular space so as to assure actuation of the ignition charge whether or not the cord is shoved to the bottom of the expansion shell or not.

Claim 19

A non-electric delay detonator adapted to be actuated by a low-energy detonating cord, said detonator including a body (1) containing a base charge (2) and a priming charge (3) in close proximity thereto and an ignition charge (11) communicating with the priming charge via a delay charge (5), said detonator body housing an expansion shell (10) which has an opening for admitting a free end of a low-energy detonating cord (21), the ignition charge being present in an annular space between the expansion shell and the detonator body and the expansion shell including cord-receiving means (14) which is positioned with respect to the ignition charge in said annular space so as to assure actuation of the ignition charge whether or not the cord is shoved to the bottom of the expansion shell or not.

Claim 20

A non-electric delay detonator substantially as described with reference to Fig. 1 of the accompanying drawings.

Claim 21

A non-electric delay detonator substantially as described with reference to Fig. 1 of the accompanying drawings.

Claim 22

A non-electric assembly-for initiating a blasting charge substantially as described with reference to Fig. 2 of the accompanying drawings.

Claim 23

A non-electric assembly-for initiating a blasting charge substantially as described with reference to Fig. 2 of the accompanying drawings.

Claim 24

The use of a non-electric detonator as claimed in claim 16 for initiating a blasting charge.